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A $60 kg$ man stands on a spring scale in a lift. At some instant, he finds that the scale reading has changed from $60 kg$ to $50 kg$ for a while and then comes again to $60 kg$ mark. What should he conclude?

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Important Questions on Laws of Motion

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A person is standing in an elevator. In which situation, he experiences weight loss ?

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

Two wooden blocks are moving on a smooth horizontal surface such that the block having mass $m$ remains stationary with respect to block of mass $M$ as shown in the figure below. The magnitude of the applied force $P$ is,

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A block of mass

M

placed inside a box descends vertically with acceleration

a

. The block exerts a force equal to one-fourth of its weight on the floor of the box. The value of

a

will be

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

Which of the following represents fundamental forces of nature?

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A boy is standing on a weighing machine inside a lift. When the lift goes upwards with acceleration

\frac{g}{4},

the machine shows the reading

50 kg .

wt. When the lift goes downward with acceleration

\frac{g}{4},

the reading of the machine in

kg

wt

. would be

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

The Nobel laureate ABDUS SALAM is known for discovery of

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

When a lift of mass

800 kg

is ascending with an acceleration of

5 m s^{- 2}

, the tension in its cable will be

______

take

(g = 10 m s^{- 2})

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

Three blocks A, B and C, of masses

4 kg, 2 kg

1 kg

and respectively, are in contact on a frictionless surface, as shown. If a force of

14 N

is applied on the

4 kg

block, then the contact force between A and B is:

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A girl drops an apple from the window of a train which is moving on a straight track with speed increasing with a constant rate. The trajectory of the falling apple as seen by the girl is

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A plumb line is suspended from a ceiling of a car moving with horizontal acceleration

a

. What will be the angle of inclination with vertical?

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

Let

G, W, S

and

E

be relative strengths of gravitational, weak nuclear, strong nuclear and electromagnetic forces. Identify the correct option

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A particle is moving along the

x

-axis with its coordinate with time

t

given by

x (t) = 10 + 8 t - 3 t^{2} .

Another particle is moving along the

y

-axis with its coordinate as a function of time given by

y (t) = 5 - 8 t^{3} .

t = 1 s,

the speed of the second particle as measured in the frame of the first particle is given as

\sqrt{v} .

Then

v (i n m s^{- 1})

is ___________.

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A curved road of diameter

1.8 km

is banked so that no friction is required at a speed of

30 m s^{- 1}

. What is the banking angle?

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A block

A

takes

2 s

to slide down a frictionless incline of

30 °

and length

l

, kept inside a lift going up with uniform velocity

v

. If the incline is changed to

45 °

, the time taken by the block, to slide down the incline, will be approximately:

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A ball of mass

m

is attached to the free end of an inextensible string of length

l

. Let

T

be the tension in the string. The ball is moving in horizontal circular path about the vertical axis. The angular velocity of the ball at any particular instant will be

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

An automobile moving with a speed of

36 km h^{- 1}

reaches an upward inclined road of angle

30 °,

its engine becomes switch off. If the coefficient of friction is

0.1

, then how much distance will automobile move before coming to rest?

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

Two blocks $A$ and $B$ are placed one over the other on a smooth horizontal surface. The maximum horizontal force that can be applied on lower block $A$ , so that $A$ and $B$ move without separation is $49 N$ . The coefficient of friction between $A$ and $B$ is

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A man weighing

60 kg

is in a lift moving down with an acceleration of

1.8 {ms}^{- 2}

. The force exerted by the floor on him is?

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

Two blocks

A

and

B

of masses

m_{A} = 1 k g

and

m_{B} = 3 k g

are kept on the table as shown in figure. The coefficients of friction between

A

and

B

0.2

and between

B

and the surface of the table is also

0.2 .

The maximum force

F

that can be applied on

B

horizontally, so that the block

A

does not slide over the block

B

is : [Take

g = 10 m / s^{2}

]

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Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A rocket is fired vertically from the earth with an acceleration of 2g, where g is the gravitational acceleration. On an inclined plane inside the rocket, making an angle

θ

with the horizontal, a point object of mass m is kept. The minimum coefficient of friction

μ_{m i n}

between the mass and the inclined surface such that the mass does not move is:

A 60 kg man stands on a spring scale in a lift. At some instant, he finds that the scale reading has changed from 60 kg to 50 kg for a while and then comes again to 60 kg mark. What should he conclude?

Important Questions on Laws of Motion

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A $60 kg$ man stands on a spring scale in a lift. At some instant, he finds that the scale reading has changed from $60 kg$ to $50 kg$ for a while and then comes again to $60 kg$ mark. What should he conclude?